1. In digital communication, 'bit rate' is defined as:
Answer:
Explanation:
Bit rate in digital communication refers to the number of bits transmitted per second, measuring the speed of data transmission.
2. The process of converting analog signals to digital form is known as:
Answer:
Explanation:
Sampling is the process of converting an analog signal into a digital signal by measuring its amplitude at discrete intervals.
3. Which modulation technique is used in most modern digital communication systems?
Answer:
Explanation:
Quadrature Amplitude Modulation (QAM) is widely used in modern digital communication systems due to its efficient use of bandwidth and high data rate capability.
4. In digital communication, 'Error Correction' refers to:
Answer:
Explanation:
Error correction involves techniques used to detect and correct errors in the received data, ensuring accurate and reliable communication.
5. The 'Shannon Capacity' theorem is used to determine:
Answer:
Explanation:
The Shannon Capacity theorem provides a formula to calculate the maximum data rate (channel capacity) for a given bandwidth and signal-to-noise ratio.
6. 'Frequency Shift Keying' (FSK) is a type of:
Answer:
Explanation:
Frequency Shift Keying (FSK) is a type of frequency modulation where the frequency of the carrier signal is varied in accordance with the digital signal.
7. The primary purpose of 'channel coding' in digital communication is to:
Answer:
Explanation:
Channel coding involves adding extra bits (redundancy) to the transmitted data for error detection and correction purposes.
8. In digital communication, 'bandwidth efficiency' measures:
Answer:
Explanation:
Bandwidth efficiency in digital communication measures the number of bits that can be transmitted per Hertz of bandwidth, indicating how efficiently the bandwidth is utilized.
9. 'Phase Shift Keying' (PSK) is commonly used in:
Answer:
Explanation:
Phase Shift Keying (PSK), a type of phase modulation, is commonly used in satellite communication due to its robustness against signal distortion.
10. The process of converting digital data into a format suitable for transmission is known as:
Answer:
Explanation:
Modulation in digital communication involves converting digital data into a format (modulated signal) that is suitable for transmission over the communication medium.
11. In digital communication, ASK stands for:
Answer:
Explanation:
Amplitude Shift Keying (ASK) is a modulation process in digital communication where the amplitude of the carrier wave is varied in accordance with the digital signal.
12. Orthogonal Frequency-Division Multiplexing (OFDM) is used to:
Answer:
Explanation:
OFDM is a method of encoding digital data on multiple carrier frequencies and is widely used in digital communication to reduce the effect of multipath fading and inter-symbol interference.
13. The 'Nyquist Rate' in digital communication refers to:
Answer:
Explanation:
The Nyquist Rate is the minimum rate at which a continuous signal must be sampled to accurately reconstruct the original signal without aliasing errors.
14. In digital communication, a 'repeater' is used to:
Answer:
Explanation:
Repeaters in digital communication systems are used to amplify and regenerate digital signals to extend the transmission range.
15. MIMO technology in digital communication refers to:
Answer:
Explanation:
MIMO (Multiple Input, Multiple Output) technology involves using multiple antennas at both the transmitter and receiver ends to improve communication performance.
16. In digital communication, 'Interleaving' is used to:
Answer:
Explanation:
Interleaving in digital communication is a technique used to rearrange the data in a message to reduce the impact of burst errors on the signal.
17. 'CDMA' in digital communication stands for:
Answer:
Explanation:
Code Division Multiple Access (CDMA) is a channel access method used by various radio communication technologies, where multiple transmitters can send information simultaneously over a single communication channel.
18. The main advantage of digital over analog communication is:
Answer:
Explanation:
Digital communication offers better noise immunity compared to analog communication, resulting in more reliable and accurate transmission of data.
19. A 'Bit Error Rate' (BER) in digital communication is a measure of:
Answer:
Explanation:
Bit Error Rate (BER) is a key performance indicator in digital communication systems, measuring the number of bit errors per unit time or per number of transmitted bits.
20. QPSK in digital communication stands for:
Answer:
Explanation:
Quadrature Phase Shift Keying (QPSK) is a digital modulation scheme that conveys two bits of digital information by changing the phase of a carrier wave.
21. In digital communication, 'channel capacity' refers to:
Answer:
Explanation:
Channel capacity in digital communication is the theoretical maximum rate at which data can be transmitted over a communication channel under ideal conditions, without introducing errors.
22. Differential Phase Shift Keying (DPSK) is used in digital communication to:
Answer:
Explanation:
DPSK, a common form of phase modulation, simplifies the receiver design by not requiring a coherent reference signal for demodulation, unlike conventional PSK.
23. 'Forward Error Correction' (FEC) in digital communication is used to:
Answer:
Explanation:
Forward Error Correction involves adding redundant data (error-correcting code) to the transmitted information, allowing the receiver to detect and correct errors without needing a reverse channel to request retransmission.
24. In digital communication, 'symbol rate' refers to:
Answer:
Explanation:
Symbol rate, also known as baud rate, is the number of symbol changes or modulation states that occur per second in a communication channel.
25. Spread Spectrum technology in digital communication is primarily used for:
Answer:
Explanation:
Spread Spectrum technology spreads the signal over a wider frequency bandwidth than necessary, improving signal security and making it more resistant to interference and eavesdropping.